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The Role of Vitamin C in Two Distinct Physiological States: Physical Activity and Sleep.
Otocka-Kmiecik, A, Król, A
Nutrients. 2020;(12)
Abstract
This paper is a literature overview of the complex relationship between vitamin C and two opposing physiological states, physical activity and sleep. The evidence suggests a clinically important bidirectional association between these two phenomena mediated by different physiological mechanisms. With this in mind, and knowing that both states share a connection with oxidative stress, we discuss the existing body of evidence to answer the question of whether vitamin C supplementation can be beneficial in the context of sleep health and key aspects of physical activity, such as performance, metabolic changes, and antioxidant function. We analyze the effect of ascorbic acid on the main sleep components, sleep duration and quality, focusing on the most common disorders: insomnia, obstructive sleep apnea, and restless legs syndrome. Deeper understanding of those interactions has implications for both public health and clinical practice.
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2.
Manipulation of Ascorbate Biosynthetic, Recycling, and Regulatory Pathways for Improved Abiotic Stress Tolerance in Plants.
Broad, RC, Bonneau, JP, Hellens, RP, Johnson, AAT
International journal of molecular sciences. 2020;(5)
Abstract
Abiotic stresses, such as drought, salinity, and extreme temperatures, are major limiting factors in global crop productivity and are predicted to be exacerbated by climate change. The overproduction of reactive oxygen species (ROS) is a common consequence of many abiotic stresses. Ascorbate, also known as vitamin C, is the most abundant water-soluble antioxidant in plant cells and can combat oxidative stress directly as a ROS scavenger, or through the ascorbate-glutathione cycle-a major antioxidant system in plant cells. Engineering crops with enhanced ascorbate concentrations therefore has the potential to promote broad abiotic stress tolerance. Three distinct strategies have been utilized to increase ascorbate concentrations in plants: (i) increased biosynthesis, (ii) enhanced recycling, or (iii) modulating regulatory factors. Here, we review the genetic pathways underlying ascorbate biosynthesis, recycling, and regulation in plants, including a summary of all metabolic engineering strategies utilized to date to increase ascorbate concentrations in model and crop species. We then highlight transgene-free strategies utilizing genome editing tools to increase ascorbate concentrations in crops, such as editing the highly conserved upstream open reading frame that controls translation of the GDP-L-galactose phosphorylase gene.
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3.
Vitamin C in Plants: Novel Concepts, New Perspectives, and Outstanding Issues.
Foyer, CH, Kyndt, T, Hancock, RD
Antioxidants & redox signaling. 2020;(7):463-485
Abstract
Significance: The concept that vitamin C (l-ascorbic acid) is at the heart of the peroxide processing and redox signaling hub in plants is well established, but our knowledge of the precise mechanisms involved remains patchy at best. Recent Advances: Ascorbate participates in the multifaceted signaling pathways initiated by both reactive oxygen species (ROS) and reactive nitrogen species. Crucially, the apoplastic ascorbate/dehydroascorbate (DHA) ratio that is regulated by ascorbate oxidase (AO) sculpts the apoplastic ROS (apoROS) signal that controls polarized cell growth, biotic and abiotic defences, and cell to cell signaling, as well as exerting control over the light-dependent regulation of photosynthesis. Critical Issues: Here we re-evaluate the roles of ascorbate in photosynthesis and other processes, addressing the question of how much we really know about the regulation of ascorbate homeostasis and its functions in plants, or how AO is regulated to modulate apoROS signals. Future Directions: The role of microRNAs in the regulation of AO activity in relation to stress perception and signaling must be resolved. Similarly, the molecular characterization of ascorbate transporters and mechanistic links between photosynthetic and respiratory electron transport and ascorbate synthesis/homeostasis are a prerequisite to understanding ascorbate homeostasis and function. Similarly, there is little in vivo evidence for ascorbate functions as an enzyme cofactor.
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4.
Possible application of high-dose vitamin C in the prevention and therapy of coronavirus infection.
Hoang, BX, Shaw, G, Fang, W, Han, B
Journal of global antimicrobial resistance. 2020;:256-262
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Abstract
Coronaviruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses increase oxidative stress in the body leading to cellular and tissue damage. To combat this, administration of high-dose vitamin C (ascorbic acid or ascorbate), in addition to standard conventional supportive treatments, has been shown to be a safe and effective therapy for severe cases of respiratory viral infection. Morbidity, mortality, infectiveness and spread of infectious diseases are dependent on the host-pathogen relationship. Given the lack of effective and safe antiviral drugs for coronaviruses, there should be more attention in supporting host immune defence, cytoprotection and immunoregulation. Implementation of high-dose vitamin C therapy could dramatically reduce the need for high doses of corticosteroids, antibacterials and antiviral drugs that may be immunosuppressive, adrenal depressive and toxic, complicating the disease course. In order to effectively fight the novel SARS-CoV-2 virus, medical professionals should explore readily available pharmaceutical and nutritional therapeutic agents with proven antioxidant, anti-inflammatory and immunosupportive properties. Supplemental vitamin C may also provide additional benefits for the prevention of viral infections, shorten the disease course and lessen complications of the disease.
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5.
Vitamin C and coronavirus.
Simonson, W
Geriatric nursing (New York, N.Y.). 2020;(3):331-332
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CEAP clinical classes C0S-C4: differences, similarities and role of Ruscus + HMC + vitamin C in patients with chronic venous disease.
Kakkos, SK, Guex, JJ, Lugli, M, Nicolaides, AN
International angiology : a journal of the International Union of Angiology. 2020;(2):118-124
Abstract
Since the publication of the CEAP classification, new research has enriched our knowledge; notably on the heritability of CVD and the genetic and environmental factors involved in this condition, as well as the symptoms apparent within the spectrum of the CEAP clinical classes and the benefits of medical treatment. Using the CEAP classification as a special theme, a symposium with the same title as the present paper was held at the annual meeting of the 2019 European Venous Forum. The lectures presented much valuable information, from which some key points can be extracted. The influence of environmental factors was demonstrated, and the fact that a large amount of information can be obtained from comprehensive history taking. There is robust evidence for heritability. Many candidate genes/loci have been identified, potentially offering new targets for treatment. More research is needed, notably using genome-wide association studies and also on microbiota, which may play a role in CVD through the inflammation pathway. Ruscus + HMC + vitamin C acts by increasing venous and lymphatic tone, protecting microcirculation, and reducing inflammation. It improves quality of life in C0S to C3 CVD patients, while a review of clinical studies and a meta-analysis have confirmed its clinical efficacy across a wide spectrum of CVD clinical classes: C0S, C1S, C2, C3 and C4. It has been awarded a Grade 1A recommendation by the international guidelines.
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Ascorbic acid is essential for inducing chromium (VI) toxicity tolerance in tomato roots.
Al-Huqail, AA, Ali, HM, Kushwaha, BK, Al-Huqail, AA, Singh, VP, Siddiqui, MH
Journal of biotechnology. 2020;:66-73
Abstract
Problem of chromium (Cr) pollution is of great scientific concern as it adversely affects crop productivity worldwide. Therefore, scientific efforts are being made to minimize Cr toxicity in crop plants by using various methods. Of these methods, use of certain chemicals like ascorbic acid (ASC), glutathione, proline, nutrients, etc. has shown promising results. Therefore, in this study, we have tested a role of ASC in regulating hexavalent chromium [Cr(VI)] toxicity in tomato roots. Chromium (VI) reduced length, dry weight, fitness and tissue density of roots due to enhanced cellular accumulation of Cr which leads to the cell death. Chromium (VI) also declined ASC pool and activity of its regenerating enzymes along with enhanced level of oxidative stress and damage to lipids and proteins. However, exogenous addition of ASC significantly reversed toxic effects of Cr(VI) in tomato roots. Furthermore, addition of lycorine (inhibitor of ASC biosynthesis) interestingly augmented Cr(VI) toxicity. However, exogenous addition of ASC reversed toxic effect of lycorine suggesting that endogenous ASC has role in alleviating Cr(VI) toxicity in tomato roots.
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8.
Vitamin C Deficiency and the Risk of Osteoporosis in Patients with an Inflammatory Bowel Disease.
Ratajczak, AE, Szymczak-Tomczak, A, Skrzypczak-Zielińska, M, Rychter, AM, Zawada, A, Dobrowolska, A, Krela-Kaźmierczak, I
Nutrients. 2020;(8)
Abstract
Recent research studies have shown that vitamin C (ascorbic acid) may affect bone mineral density and that a deficiency of ascorbic acid leads to the development of osteoporosis. Patients suffering from an inflammatory bowel disease are at a risk of low bone mineral density. It is vital to notice that patients with Crohn's disease and ulcerative colitis also are at risk of vitamin C deficiency which is due to factors such as reduced consumption of fresh vegetables and fruits, i.e., the main sources of ascorbic acid. Additionally, some patients follow diets which may provide an insufficient amount of vitamin C. Moreover, serum vitamin C level also is dependent on genetic factors, such as SLC23A1 and SLC23A2 genes, encoding sodium-dependent vitamin C transporters and GSTM1, GSTP1 and GSTT1 genes which encode glutathione S-transferases. Furthermore, ascorbic acid may modify the composition of gut microbiota which plays a role in the pathogenesis of an inflammatory bowel disease.
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Treating sepsis with vitamin C, thiamine, and hydrocortisone: Exploring the quest for the magic elixir.
Obi, J, Pastores, SM, Ramanathan, LV, Yang, J, Halpern, NA
Journal of critical care. 2020;:231-239
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Abstract
The administration of ascorbic acid (vitamin C) alone or in combination with thiamine (vitamin B1) and corticosteroids (VCTS) has recently been hypothesized to improve hemodynamics, end-organ function, and may even increase survival in critically ill patients. There are several clinical studies that have investigated the use of vitamin C alone or VCTS in patients with sepsis and septic shock or are ongoing. Some of these studies have demonstrated its safety and potential benefit in septic patients. However, many questions remain regarding the optimal dosing regimens and plasma concentrations, timing of administration, and adverse effects of vitamin C and thiamine. These questions exist because the bulk of research regarding the efficacy of vitamin C alone or in combination with thiamine and corticosteroids in sepsis is limited to a few randomized controlled trials, retrospective before-and-after studies, and case reports. Thus, although the underlying rationale and mechanistic pathways of vitamin C and thiamine in sepsis have been well described, the clinical impact of the VCTS regimen is complex and remains to be determined. This review aims to explore the current evidence and potential benefits and adverse effects of the VCTS regimen for the treatment of sepsis.
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10.
Mini-Review on the Roles of Vitamin C, Vitamin D, and Selenium in the Immune System against COVID-19.
Bae, M, Kim, H
Molecules (Basel, Switzerland). 2020;(22)
Abstract
Low levels of micronutrients have been associated with adverse clinical outcomes during viral infections. Therefore, to maximize the nutritional defense against infections, a daily allowance of vitamins and trace elements for malnourished patients at risk of or diagnosed with coronavirus disease 2019 (COVID-19) may be beneficial. Recent studies on COVID-19 patients have shown that vitamin D and selenium deficiencies are evident in patients with acute respiratory tract infections. Vitamin D improves the physical barrier against viruses and stimulates the production of antimicrobial peptides. It may prevent cytokine storms by decreasing the production of inflammatory cytokines. Selenium enhances the function of cytotoxic effector cells. Furthermore, selenium is important for maintaining T cell maturation and functions, as well as for T cell-dependent antibody production. Vitamin C is considered an antiviral agent as it increases immunity. Administration of vitamin C increased the survival rate of COVID-19 patients by attenuating excessive activation of the immune response. Vitamin C increases antiviral cytokines and free radical formation, decreasing viral yield. It also attenuates excessive inflammatory responses and hyperactivation of immune cells. In this mini-review, the roles of vitamin C, vitamin D, and selenium in the immune system are discussed in relation to COVID-19.